Silicon carbide (SiC) is expected to be used as a material for a next-general semiconductor device. SiC has better physical properties than silicon (Si). For example, SiC has a bandgap that is three times wider than that of Si, a breakdown field strength that is about ten times higher than that of Si, and a thermal conductivity that is about three times higher than that of Si. These characteristics can be used to achieve a semiconductor device which has low loss and can operate at a high temperature.
However, for example, when silicon carbide is used to form a metal oxide semiconductor field effect transistor (MOSFET), there is the problem that the mobility of carriers is reduced. It is considered that the mobility of carriers is reduced by the influence of an interface state between a silicon carbide layer and a gate insulating layer.
As a method for reducing the interface state, there is a method that terminates the surface of the silicon carbide layer with a termination element.